We're all part of the market....every one who buys/sells can affect trading. 

Even a piker buying 1,000 shares can have an impact, especially if the buy order is filled by someone who doesn't have the shares to hand over.  Obviously there are players with bigger footprints than others....if HL decides to start dumping, there would likely be a big shift...unless they engaged some promotional outfits and/or managed to get RVX talked about far and wide.